The face detection algorithm seems to lack a very simple parameter for the plausibility of the detection of a person: It is more likely that the same persons are on photos which are all taken at the same day.

This would mean that the face detection algorithm not just analyses each photo as an individual one, it would mean that the algorithm has to detect a whole series of photos, e.g. all photos in a given folder.

Currently the algorithm is suggesting persons from photos which are years old. I think the detection ration could significantly improved if the photos would be analysed in the context of a folder or day.